Publications by authors named "Marion Fischer-Le Saux"

Article Synopsis
  • Early-branching xanthomonads, or clade-1 xanthomonads, consist of important plant pathogens that mostly affect monocotyledonous plants, with seven described species including those affecting sugarcane and cereals.
  • Recent genomic studies, including long-read sequencing, identified three novel xanthomonad species from New Zealand flax, common bean, and banana, highlighting their unique phylogenetic position within this clade.
  • The research uncovered new genetic features, such as genes for coronatine-like compounds and an atypical flagellar gene cluster in one strain, which could advance our understanding of their evolution and pathogenicity.
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is the causal agent of blight and canker on grapevine. Only a few data are available on this species implying that the occurrence of this pathogen may be underestimated, and its actual ecological niche may not be understood. Moreover, its genetic diversity is not well known.

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comprises a number of economically important fruit tree pathogens classified within different pathovars. Dozens of nonpathogenic and taxonomically unvalidated strains are also designated as , leading to a complicated taxonomic status in the species. In this study, we have evaluated the whole-genome resources of all available spp.

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In summer 2019, widespread occurrence of crown gall disease caused by spp. was observed on commercially grown ornamental plants in southern Iran. Beside agrobacteria, pale yellow-pigmented Gram-negative strains resembling the members of were also associated with crown gall tissues on weeping fig (Ficus benjamina) and sp.

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Background: The species Xanthomonas arboricola comprises up to nine pathovars, two of which affect nut crops: pv. juglandis, the causal agent of walnut bacterial blight, brown apical necrosis, and the vertical oozing canker of Persian (English) walnut; and pv. corylina, the causal agent of the bacterial blight of hazelnut.

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is the causal agent of bacterial canker on tea plants. There is no complete genome sequence available for , a close relative of the species and , thus limiting basic research for this group of pathogens. Here, we release a high-quality complete genome sequence for the type strain, CFBP 4691.

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Assessment of the taxonomy and diversity of Xanthomonas strains causing bacterial leaf spot of lettuce (BLSL), commonly referred to as Xanthomonas campestris pv. vitians, has been a long-lasting issue which held back the global efforts made to understand this pathogen. In order to provide a sound basis essential to its study, we conducted a polyphasic approach on strains obtained through sampling campaigns or acquired from collections.

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The bacterial plant pathogen is the causal agent of yellow disease of and other ornamental plant genera. There is no available complete genome for , limiting basic research for this pathogen. Here, we release a high-quality complete genome sequence for the type strain, CFBP 1156.

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The species corresponds to a complex, including two subspecies with validly published names, two proposed subspecies and two new species, and Recent studies suggested that this complex needed revision. We examined the taxonomic status of 144 strains isolated from a wide range of plant species, various geographical origins and waterways. Sequences of the , and housekeeping genes clustered 114 of these strains together within a not yet described clade.

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Cases of emergence of novel plant-pathogenic strains are regularly reported that reduce the yields of crops and trees. However, the molecular mechanisms underlying such emergence are still poorly understood. The acquisition by environmental non-pathogenic strains of novel virulence genes by horizontal gene transfer has been suggested as a driver for the emergence of novel pathogenic strains.

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Three isolates obtained from symptomatic nectarine trees (Prunus persica var. nectarina) cultivated in Murcia, Spain, which showed yellow and mucoid colonies similar to Xanthomonas arboricola pv. pruni, were negative after serological and real-time PCR analyses for this pathogen.

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Here, we present the high-quality draft genome sequence of sp. strain Ferrero, an actinobacterium belonging to a novel species isolated as an environmental contaminant in a bacterial cell culture. The assembled genome of 3,694,888 bp in 49 contigs has a G+C content of 71.

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Article Synopsis
  • Understanding the evolutionary history and transmission patterns of virulence factors, specifically the type three secretion system (T3SS), is crucial for addressing new pathogens, particularly in the Xanthomonas genus that poses a significant risk to plant health.
  • Phylogenomic analysis of 82 Xanthomonas genomes revealed three ancestral acquisitions of the Hrp2 T3SS cluster, followed by fluctuations in its presence due to losses in some strains and re-acquisitions in others, emphasizing a complex evolutionary history shaped by mutations and gene transfer.
  • A reduced core effectome associated with commensal strains suggests adaptations to evade plant defenses, while successful pathogens accumulate diverse type 3 effector genes, highlighting the ongoing evolution of T3
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How pathogens coevolve with and adapt to their hosts are critical to understanding how host jumps and/or acquisition of novel traits can lead to new disease emergences. The Xanthomonas genus includes Gram-negative plant-pathogenic bacteria that collectively infect a broad range of crops and wild plant species. However, individual Xanthomonas strains usually cause disease on only a few plant species and are highly adapted to their hosts, making them pertinent models to study host specificity.

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The acquisition of virulence-related genes through horizontal gene transfer can modify the pathogenic profiles of strains and lead to the emergence of new diseases. Xanthomonas arboricola is a bacterial species largely known for the damage it causes to stone and nut fruit trees worldwide. In addition to these host-specific populations called pathovars, many nonpathogenic strains have been identified in this species.

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Background: The bacterial species Xanthomonas campestris infects a wide range of Brassicaceae. Specific pathovars of this species cause black rot (pv. campestris), bacterial blight of stock (pv.

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Strains of Xanthomonas translucens pv. graminis cause bacterial wilt on several forage grasses. A draft genome sequence of pathotype strain CFBP 2053 was generated to facilitate the discovery of new pathogenicity factors and to develop diagnostic tools for the species X.

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Xanthomonas campestris pv. campestris is the causal agent of black rot on Brassicaceae. The draft genome sequences of strains CFBP 1869 and CFBP 5817 have been determined and are the first ones corresponding to race 1 and race 4 strains, which have a predominant agronomic and economic impact on cabbage cultures worldwide.

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Short, Gram-negative-staining, rod-shaped bacteria were isolated from crushed bodies of Russian wheat aphid [Diuraphis noxia (Kurdjumov)] and artificial diets after Russian wheat aphid feeding. Based on multilocus sequence analysis involving the 16S rRNA, atpD, infB, gyrB and rpoB genes, these bacterial isolates constitute a novel clade in the genus Erwinia, and were most closely related to Erwinia toletana. Representative distinct strains within this clade were used for comparisons with related species of Erwinia.

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Xanthomonas arboricola is conventionally known as a taxon of plant-pathogenic bacteria that includes seven pathovars. This study showed that X. arboricola also encompasses nonpathogenic bacteria that cause no apparent disease symptoms on their hosts.

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Deep and comprehensive knowledge of the genetic structure of pathogenic species is the cornerstone on which the design of precise molecular diagnostic tools is built. Xanthomonas arboricola is divided into pathovars, some of which are classified as quarantine organisms in many countries and are responsible for diseases on nut and stone fruit trees that have emerged worldwide. Recent taxonomic studies of the genus Xanthomonas showed that strains isolated from other hosts should be classified in X.

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Xanthomonas translucens pv. cerealis is the causal agent of bacterial leaf streak on true grasses. The genome of the pathotype strain CFBP 2541 was sequenced in order to decipher mechanisms that provoke disease and to elucidate the role of transcription activator-like (TAL) type III effectors in pathogenicity.

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We report the draft genome sequence of the Xanthomonas cassavae type strain CFBP 4642, the causal agent of bacterial necrosis on cassava plants. These data will allow the comparison of this nonvascular pathogen with the vascular pathogen Xanthomonas axonopodis pv. manihotis, both infecting the same host, which will facilitate the development of diagnostic tools.

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